Electric-arc lamp



Feb. 15, 1927.

J. A. HEANY ELECTRIC ARC LAMP Original led Jun 11', 1917 Patented Feb 15, 1927 TBS JOHN AIiLEN HEANY, OF NEW HAVEN, CONNECTICUT, ASSIGNOR T0 HEANY LABORA- TORIES, INC., 0]? NEW HAVEN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

ELECTRIC-ARC LAMP.

Application filed June 11, 1917, Serial No. 174,105. Renewed January 25, 1926.

The invention relates to electric arc lamps which operate on very low wattages and at the ordinary commercial voltages and will maintain high efficiencies even in the smaller sizes ranging as low as ten or fifteen candle power. To this end, the invention comprises a lamp, involving a'container or envelope, preferably adapted for connection in the ordinary incandescent lamp socket, and con taining an inert gas, preferably under diminished pressure, and two electrodes, be-

tween wliich the arc is maintained, conneeted to suitable lead wires, at least one of which comprises a rod-like element formed of material which is a COlldllCtOI of the second class, which is non-conductive when cold, but becomes conductive when highly heated, surrounded in part by a sleeve or envelope of highly refractory oxidewvllicli isa mm-comluctor, but which incandesces at a high temperature, the composite electrode thus constituted being associated with a coil oi" highly refractory wire, such as tungsten, which serves as a heating element and ballast and in turn is connected to one end of the second class conductor portion of the electrode and to one branch of a separable shunt around the are gap, the other branch of which shunt is connected to the opposite electrode, which in turn is preferably supported by a thermostat which serves to move the electrodesapart to proper arcing distance and also to break the shunt, after the are has been established, the relation of the parts of the device being such that the highly refractory wire coil serves as ballast resistance in series with the are, as a heater to raise the second class conductor electrode to conductivity and also produces ionization of the gas surrounding the electrodes to start the are, constitutes a heater for operating the thermostat and serves as a luminant per se to augment the light emittedat the arc. v

The invention is illustrated in the accompanying drawings, in which,

Fig. 1 illustrates a lamp having the two arcing electrodes of substantially the same thermostat 10 which is mounted 1n a glass construction.

Fig. 2 shows a modification in which one of the electrodes comprises a body of highly refractory metal, such as tungsten or tung-' sten alloy.

Referring to the drawings, 1 indicates a bulb or contalner of the type usually employed, in incandescent filament lamps,

adapted for the usual" socket connection, which is exhausted of air and supplied with an inert gas, such as nitrogen, argon,'or the like, preferably under diminished pressure. The bulb is provided with the usual form of glass neck 2 in which are mounted the usual supply leads connected to the lamp terminals, to one of which leads is connected the conducting and supporting wire 3, which at its lower end is connected to one end of a helix or coil of highly refractory wire, such as tungsten or the like, within which coil is mounted one of the' arcing electrodes whichcon'iprises a central rod like core 6 made of materials which constitute a conductor of the second class, such as' an admixture of oxides of zirconium, thorium and yttrium, which core (3 is surrounded in part by a sleeve 5 of highly refractory oxide, such as oxide of thorium which is a non-conductor, but which-incandesces when raised to a high temperature. The electrode 6 is carried by the snp iorting wire 3 through the medium of the clamp 3. The inner end of the coil 4 is in electrical contact with the forward end of the core 6, which preferably projects beyond the sleeve 5 and constitutes the arcing terminal of the electrode, and said coil is extended to form a lead 12 terminating in a contact 14.

As illustrated in Fig. 1, the opposite electrode is formed substantially like that just described, and comprises a coil 7 ofv tungsten wire or the like surroumlingflan electrode con'iprising a core 9 similar to core 6 of the opposite electrode, and a sleeve 8 of "re fractory oxide surrounding said core. This electrode is supported by means of the clamp 16 carried by the wire 17 which is fused to the thermostat. The inner end of the coil 7 is extended in a lead 13, provided with a terminal contact 15, which is normally in engagen'ient with-contact 14, said leads 12 and 13 and contacts 14 and 15 constituting a normally closed by-pass around the arc gap in series with the coils 4 and 7.

The outer end of coil 7 is connected to a neck 2 and is connected to the opposite terminal lead of the lamp hyconductor 11.

' When current is turned into the lamp, it flows fromone terminal by way of conductor 3 through coil 4, by-pass 12, 14, 15,

the other terminal of the lamp. The imme- '13, coil 7, thermostat 10,, wire 11, back to sleeves 5 and 8 to incandesce.

diate effect of the passage of the current is to raise the coils-4c and 7 to incandescence,

which heats the electrodes to render the cores 6 and 9 thereof conductive and causes the The heat generated ionizes the gas between and around the electrodes to start the, are becoils acts as ballast resistance for the are ing electrode shown in Fig. 1.

and in addition thereto serve as incandescent luminants per se.

In the modification shown in Fig. 2, the left hand electrodeand its" accessories are substantially identical with the correspond- The right hand electrode, however, comprises a'bulbous termin'al9, preferably of highly rcfractory metal, such astungsten or a tungsten alloy, mounted on the end of a conductor 7 which in turn is connected to the thermostat 10. In this particular form, the coil-4 is made of such size and dimensions as to afford thenecessary ballast resistance for the ,arc and also the requisite heating capacity to raise tlie temperature of the electrode to the desired degree What I claim is c 1. An electric arc lamp comprising a container, electrodes therein, at least one of which comprises a core ofsecond class conducting material, having an envelope of highly ref ctory non-conducting oxide, :1

giallast coil of highly refractory metallic wire surroundingthe electrode and connected to the com, a normally closed shunt around the terminals of the electrodes and in series with said refractory wire, and

means adapted to break the shunt whenthe electrode is .heated sufficiently to render the;

core thereof conductive.

2. An electric arc lamp comprising a container, electrodes therein, at least one of which comprises a core of second class ,conducting material, having an envelope of highly refractory non-conducting oxide, a heating and ballast coil of highly refractory metallic wire surounding the electrode and connected to the core, a normally closed shunt. around the terminalscf the electrodes and in series with said refractory wire, and a thermostat adapted to move one of said electrodes away from the other and to break the shunt when the electrode is heated sulficiently to cause-the core thereof to become conductive. V

3. An electric arc lamp comprising a con-'1 tainer, electrodes therein which comprise cores of second-class conducting material, having envelopes of highly refractory nonconductingl material, heating and ballast coils of highly refractory metallic wire connected-to the cores, a normally closed shunt around the terminals of the electrodes and intemperatures, non-conducting envelop-cs en-" closing the conductive material, means for inducting an are .between said electrodes comprising a heating coil positioned adjacent the electrodes, and disconnectible contacts' connecting the electrodes.

6. An electric lamp 'comprisng a container, electrodes therein having cores of material electrically conductive at operating temperatures, non-conducting envelopes enclosing the conductive material, means 'for inducling an arc. between said electrodes. comprising .a heating coil positioned adjacent the electrodes, disconneclible contacts connecting the electrodes, and temperature controlled means for breaking said contacts -'r'c, )1 if c 7 An eltctl lamp u 11 p11 mg l on tamer, electrodes therein having cores of material electrically conductive at operating tempcraturcs,. non-conducting envelopes around and enclosing the conductive material, means for inducting an are between said electrodes, comprising a heating coil positioned adjacent the electrodes, disconnectible contacts connecting the electrodes, and me: ns including a thermostat in series with sai heating coil. for making the'coil ineffective.

In testimony whereof I aflix my signature.

JOHN ALLEN HEANY. 

